Recently, the interest in the safety at the time of collision of the car is increased and the application of an airbag system is enlarged.
The airbag system is an apparatus for protecting a passenger in the car with being developed at the time of collision of the car.
The airbag system may comprise a sensor module capable of detecting a collision of a car, a control section for receiving a signal detected by the sensor module and deciding the development of an airbag according to the strength of the signal, and the airbag which is developed according to the signal of the control section.
The sensor module consists in general of a collision sensor and is mounted on a main collision expecting portion of the car body, and the airbag is provided at main portion of the inside of the space where the passenger sits.
Therefore, when a car collides, an impact therefrom is transmitted to the sensor module, and the control section decides whether the air bag is deployed by judging the amount of the impact measured by the sensor module, and develops the airbag when the amount of the impact is judged to reach a predetermined level.
However, the conventional airbag system described above has problems as follows:
First, the sensor module of the conventional airbag system is fixed to the car body by means of a bolt and the like as described in Korean Utility Model Application No. 20-1999-0024432, which has been already laid open, such a fixing method requires an additional separate process in the assembly of the car body, thereby making the production process of a car complicated.
Second, since the sensor module of the conventional airbag system is fixed to the car body by means of a bolt and the like, there is a problem in that a miss operation of the sensor may happen in the case where the fastening of the bolt is loosened due to a continuous vibration or external force caused during the travel of the car.
Third, the sensor module of the conventional airbag system detects the development of the airbag by using the collision sensor, and the collision sensor is configured to detect only when a significantly large impact is directly applied to prevent the miss operation. Therefore, there may arises a case of not capable of detecting the time when the airbag has to be developed such as a case where the impact is applied to the portion where the collision sensor is not provided or a case where the amount of impact is small, however, the amount of deformation of a car body is large.
Fourth, the conventional airbag system connects the collision sensor and an ECU of the car body by means of wiring, however, the connection operation may require an additional process and there may be a risk of miss operation in a case where the wire is defective upon the aging of the car.